12012138 has 20 divisors (see below), whose sum is σ = 26916450. Its totient is φ = 4003992.

The previous prime is 12012137. The next prime is 12012157. The reversal of 12012138 is 83121021.

It can be written as a sum of positive squares in only one way, i.e., 9753129 + 2259009 = 3123^2 + 1503^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12012138.

It is not an unprimeable number, because it can be changed into a prime (12012131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 36913 + ... + 37236.

Almost surely, 2^12012138 is an apocalyptic number.

12012138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12012138 is an abundant number, since it is smaller than the sum of its proper divisors (14904312).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12012138 is an equidigital number, since it uses as much as digits as its factorization.

12012138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74163 (or 74154 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 12012138 is about 3465.8531417243. The cubic root of 12012138 is about 229.0200143958.

Adding to 12012138 its reverse (83121021), we get a palindrome (95133159).

The spelling of 12012138 in words is "twelve million, twelve thousand, one hundred thirty-eight".